Movable or slidable construction member connections can be utilized in building design to prevent or limit damage due to varying or dynamic loads. Varying loads can arise from movement of equipment and personnel in the building as well as from environmental factors such as high winds and seismic activity. Flexing of construction members under varying load is expected and acceptable within code-specified limits. However, such flexing often means that some connections between members can cause damage if some relative movement between the connected members is not allowed. The building industry has recognized this problem. Movement between connected members has been accommodated by having sliding connections between the members to permit limited relative movement between the members while keeping the members otherwise securely connected together.
An approach commonly used is that of a slotted connection. In a typical configuration, a connector in the form of a plate or bracket is rigidly secured to or part of one of the members and slidably connected to the other member by means of one or more slots and fasteners. Typically the plate has slots, and shouldered or bushed screws, are projected through slots and into the other member. The screws are tightened to secure the members together but yet permit the members some range of relative sliding movement. The head of the fastener is prevented by the shoulder or bushing from clamping against the connector plate so that the plate can move along the length of the slot. For a more complete and detailed description of such connection devices, reference is made to U.S. Pat. Nos. 5,906,080; 6,612,087; 5,467,566; and, 7,503,150; the disclosures of these patents are expressly included herein by reference.
The degree to which such devices function as intended is dependent upon proper installation. For example, should a shouldered screw be inserted and tightened off center in the slot, the shoulder would overlap and clamp the plate to the member. This clamping would render the connection more or less rigid and not slidable. Avoiding this kind of improper installation requires time and installer dexterity to properly align the screw in the slot.
A need exists for a connection assembly that will provide for easy and accurate screw placement to prevent inadvertent clamping together of the building members being connected and to thus facilitate slidable connection between the members.